The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2001-213495 filed on Jul. 13, 2001 the entire contents thereof is hereby incorporated by reference.
1. Field of the Invention
This invention relates to a sensor arrangement structure for an engine for a personal watercraft.
2. Description of Background Art
Conventionally, a personal watercraft is known wherein an engine for driving a jet propulsion pump is provided in a watercraft body surrounded by a hull and a deck.
In a personal watercraft of the type described, an intake duct for supplying air into the watercraft body is provided. From an opening of the intake duct on the inner side of the watercraft body, water is sometimes admitted in the form of droplets into the watercraft body together with air. If an engine controlling sensor is exposed to the water, then there is the possibility that a wrong signal may be inputted from the sensor to a control apparatus for the engine to cause the engine to operate inappropriately.
In order to eliminate such a disadvantage as just described, a personal watercraft has been proposed wherein an engine controlling sensor is disposed above an opening of an intake duct on the inner side of a watercraft body as disclosed in Japanese Patent Laid-Open No. Hei 10-318014.
With the personal watercraft described above, since the engine controlling sensor is provided above the opening of the intake duct on the inner side of the watercraft body, even if water is introduced in the form of droplets into the space in the watercraft body when the atmospheric air outside the watercraft body is introduced into the space in the watercraft body through the intake duct during operation of the personal watercraft, the water is less likely to splash the sensor, and the engine is likely to operate appropriately.
Since usually a personal watercraft of the type described is frequently utilized for leisure, such a situation where some water enters the inside of the watercraft body occurs frequently.
Further, a personal watercraft frequently undergoes sudden turns or violent rolling because it is in most cases utilized for leisure.
In such a situation as just described, in the conventional personal watercraft described above, since the engine controlling sensor is merely disposed above the opening of the intake duct on the inner side of the watercraft body, if the personal watercraft turns suddenly or rolls violently in a state wherein some water is admitted in the watercraft body, then the water in the watercraft body is likely to splash the engine controlling sensor. Therefore, the conventional personal watercraft described above still has the possibility that the engine may be hindered from operating appropriately.
In other words, the prior art described above does not present a sufficient countermeasure for prevention of the engine controlling sensor from being splashed with water.
The object of the present invention resides in a solution of such a problem as described above and the provision of a sensor arrangement structure for an engine for a personal watercraft which takes a sufficient countermeasure for prevention of an engine controlling sensor from being splashed with water so that the engine operates appropriately.
In order to attain the object described above, a sensor arrangement structure for an engine of a personal watercraft for driving a jet propulsion pump is provided in a watercraft body surrounded by a hull and a deck with a throttle body and a surge tank contiguous to the throttle body being provided on an intake side of the engine. A horizontal partition assembly extends in a forward and rearward direction and extendes in a substantially horizontal direction at an upper portion of the engine formed from the throttle body and the surge tank with a sensor for controlling the engine is disposed above the horizontal partition assembly.
According to the present invention, the sensor arrangement structure for an engine of a personal watercraft is provided with a supercharger which communicates with the surge tank through an intercooler and a supercharged pressure sensor and/or a temperature sensor of air of the supercharger is provided above the surge tank with the intercooler being disposed just below the surge tank.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft includes an intake pressure sensor for detecting an intake pressure of the throttle body on the downstream side of the throttle that is disposed rather near to a head cover of the engine between the head cover and the surge tank.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft includes the intake pressure sensor attached to the head cover in such a state that the intake pressure sensor is spaced away from an upper face of the throttle body.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft includes an opening which is closed with a removable lid member provided in an upper portion of the deck, and the sensor is exposed to the opening.
According to the present invention, a sensor arrangement structure for an engine for a personal watercraft is structured such that an engine for driving a jet propulsion pump is provided in a watercraft body surrounded by a hull and a deck with a throttle body and a surge tank contiguous to the throttle body being provided on an intake side of the engine. A horizontal partition assembly extends in a forward and rearward direction and extends in a substantially horizontal direction at an upper portion of the engine and is formed from the throttle body and the surge tank. A sensor for controlling the engine is disposed above the horizontal partition assembly. Therefore, even if the personal watercraft turns suddenly or rolls violently in a state wherein some water is admitted into the watercraft body and the water in the watercraft body moves toward the sensor, the water is in most cases hindered by the horizontal partition assembly formed from the throttle body and the surge tank in such a state that it extends in a forward and rearward direction and extends in a substantially horizontal direction above the engine, and is less likely to splash the sensor.
Accordingly, such a situation wherein the sensor for controlling the engine becomes wet with water is less likely to occur. Thus, a situation wherein a wrong signal is inputted from the sensor to a control apparatus for the engine is less likely to occur. Therefore the engine is likely to operate appropriately.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft according to the present invention is structured such that the engine is provided with a supercharger which communicates with the surge tank through an intercooler and a supercharged pressure sensor and/or a temperature sensor of air of the supercharger is provided above the surge tank with the intercooler being disposed just below the surge tank. Therefore, even if the water in the watercraft body is excited and tends to move toward the sensor, it is hindered also by the intercooler disposed just below the surge tank and is less likely to splash the supercharged pressure sensor and/or the temperature sensor.
Accordingly, a situation wherein the sensor for controlling the engine with a supercharger becomes wet with water is less likely to occur. Thus, a situation wherein a wrong signal is inputted from the sensor to the control apparatus for the engine with a supercharger is less likely to occur. Therefore, the engine with a supercharger is likely to operate appropriately.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft includes an intake pressure sensor for detecting an intake pressure of the throttle body on the downstream side of the throttle valve that is disposed rather near to a head cover of the engine between the head cover and the surge tank. Therefore, the intake pressure sensor is disposed at a high position at substantially the center in the widthwise direction of the watercraft body.
Accordingly, even if the water in the watercraft body is excited and tends to move toward the intake pressure sensor, such a situation wherein the intake pressure sensor becomes wet with water is less likely to occur. Thus, a situation wherein a wrong signal from the intake pressure sensor is inputted to the control apparatus for the engine is less likely to occur. Therefore the engine is likely to operate appropriately.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft includes the intake pressure sensor attached to the head cover wherein the intake pressure sensor is spaced away from an upper face of the throttle body. Therefore, even if the intake pressure sensor should be splashed with water or some water should stay on the upper face of the throttle body, the water is retracted (removed) rapidly from around the intake pressure sensor.
Accordingly, even if the intake pressure sensor becomes wet with water, this state is eliminated in a short time, and a situation wherein there is the possibility that a wrong signal may be inputted from the intake pressure sensor to the control apparatus for the engine is likely to be eliminated in a short time, and the engine is likely to operate appropriately.
Further, since the intake pressure sensor is attached to the head cover, the intake pressure sensor can be attached readily in a state wherein it is accurately spaced away from the upper face of the throttle body.
According to the present invention, the sensor arrangement structure for an engine for a personal watercraft includes an opening that is closed with a removable lid member provided in an upper portion of the deck, and the sensor is exposed to the opening. Therefore, if the lid member is opened, then a checking operation of the sensor can be performed readily.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.